Jump to:

Disease/Disorder

Definition

Neurogenic bowel (NB) is bowel dysfunction in individuals with nervous system diseases or injuries, resulting in failure to evacuate the bowel (fecal constipation, fecal impaction) or failure to contain stool (fecal incontinence).

Etiology

NB can be seen in multiple conditions, including spinal cord injury (SCI), brain injury, stroke, spina bifida, Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), peripheral nerve injuries and diabetes mellitus, among others. Much of the literature on NB is in the SCI population.

Epidemiology including risk factors and primary prevention

Prevalence of NB depends on the diagnosis. Over 80% of SCI patients have some degree of bowel dysfunction, with moderate to severe symptoms reported by 39-50%.1 It has been reported that 95% of patients with SCI required at least one therapeutic procedure to initiate defecation.2 Fecal incontinence has been reported in up to 70% of patients with MS, 56% of patients with cerebral palsy, 68% of patients with spina bifida, 23% of patients with stroke, and 24% of patients with Parkinson’s disease. Constipation has been reported in up to 70% of MS patients, 25% of stroke patients, and 20-81% of people with Parkinson’s disease.3,4

Patho-anatomy/physiology

The gastrointestinal system is controlled by the autonomic nervous system, including the enteric, parasympathetic, and sympathetic nervous systems. The enteric nervous system (ENS) is located within the gut itself and controls peristalsis and secretion. Auerbach’s plexus and Meissner’s plexus are part of the ENS. Parasympathetic innervation includes the vagus nerve (upper GI tract to the splenic flexure of the colon) and sacral nerves 2-4 (to distal colon and rectum). Sympathetic innervation originates from T9-L2 (to colon and rectum).  Parasympathetic activity generally promotes peristalsis and defecation, while sympathetic activity slows peristalsis and promotes storage. The external anal sphincter has somatic innervation from the pudendal nerve (S2-4) and is under voluntary control.1

Normal reflexes include the defecation reflex (stretch of rectal wall stimulates rectal wall contraction), rectoanal inhibitory reflex (stretch of rectal wall relaxes internal anal sphincter), and the gastrocolic reflex (stomach stretch stimulates colonic motility).1

Neurogenic bowel dysfunction can result from multiple factors, including autonomic dysfunction, altered reflexes, altered sphincter tone, altered sensation and strength, and mobility or cognitive impairments. The type of dysfunction depends on the level and severity of the lesion and is commonly divided into reflexic or areflexic bowel (Table 1). Lesions proximal to the conus medullaris typically result in a reflexic bowel (also termed as upper motor neuron bowel syndrome), whereas lesions that affect the parasympathetic cell bodies at the conus medullaris, their axons in the cauda equina, or the pelvic nerve typically result in an areflexic bowel (also termed as lower motor neuron bowel syndrome) due to a loss of coordinated bowel contractions. In a reflexic bowel, there is increased colonic wall and anal sphincter tone due to hyperreflexia of the colon and external anal sphincter.5 Stool propulsion still occurs due to intact reflexes but may be less efficient and shows prolonged colonic transit time. Due to increased sphincter tone and possible dyssynergia, reflexic bowel is less prone to incontinence, but may promote retention and constipation. With an areflexic bowel, there is decreased spinal cord-mediated peristalsis, and colonic and sphincter tone is reduced. This results in prolonged colonic transit times, constipation, and tendency for incontinence. Rectosigmoid emptying is reduced in both, but reflexic bowel can take advantage of reflex defecation.1

The dysfunction in PD is distinct and incompletely understood. GI dysfunction is thought to be one of the earliest and most common nonmotor symptoms in PD, related to lesions in the enteric nervous system and pelvic floor dystonia. Upper GI symptoms are also more prevalent compared to SCI.6

Table 1 – Features of Reflexic versus Areflexic Bowel Dysfunction

Reflexic BowelAreflexic Bowel
Constipation and fecal retentionConstipation and incontinence
Delayed colonic transit, less delay in rectumVery delayed colonic transit throughout
Anal area appears normalFlattened scalloped appearance of anal area
Normal or increased anal sphincter toneReduced anal sphincter tone
Reflex defecation is present.Absent reflex defecation
Anocutaneous and bulbocavernosus reflexes are present or increasedAnocutaneous and bulbocavernosus reflexes are absent or decreased
Target stool consistency is soft-formedTarget stool consistency is firm but not hard
 Prone to rectal prolapse
Bowel care every 1-3 days is recommendedDaily bowel care is recommended to avoid fecal incontinence
Use rectal suppositories to promote peristalsis and evacuationRectal suppositories are not usually effective
Digital stimulation can be used to assist in evacuationDigital stimulation is not effective; manual evacuation may be necessary

Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)

New onset/acute: After SCI, there is temporary loss or depression of all or most reflex activity below the level of the lesion, which may last hours to weeks (spinal shock). During this time period, there is less reflex-mediated defecation.7,8 Studies on the natural history of NB in other populations are lacking.

Subacute: In SCI, once spinal shock has resolved, a bowel program can be initiated. The underlying pathophysiology (reflexic vs. areflexic) will guide the interventions to be used (Table 1).

Chronic/stable: During this time period, treatment continues using an appropriate bowel program. Hemorrhoids can develop if high pressures are present due to hard stool passage. In areflexic bowel, chronic passage of large hard stools can result in rectal prolapse with an overstretched, non-competent sphincter.8 There is some evidence that symptoms may become more severe with time since SCI.1

Specific secondary or associated conditions and complications

Complications due to neurogenic bowel include, but are not limited to, ileus, gastroesophageal reflux disease (GERD), autonomic dysreflexia (AD), pain, distention, nausea, anorexia, impaction, constipation, diarrhea, delayed evacuation, and unplanned evacuation. Severe complications may include fecal impaction, bowel obstruction, and megacolon. An appropriate bowel program should minimize or eliminate complications.7 Bowel dysfunction also correlates with depression and quality of life.1 Furthermore, unplanned evacuations and extended time spent on the bowel program significantly contribute to psychological distress.9

Essentials of Assessment

History

This should include pre-injury gastrointestinal function and medical conditions, current bowel program, current symptoms including abdominal distention, respiratory compromise, early satiety, nausea, evacuation difficulty, unplanned evacuations, pain, autonomic dysreflexia, constipation, diarrhea, and rectal bleeding. It is vital to troubleshoot these common symptoms to troubleshoot appropriately and to prevent recurrence. For instance, autonomic dysreflexia can be due to a pain stimulant which can consist of any of the following: hemorrhoids or fissures, overdistended bowel (due to constipation, impaction, inconsistent bowel care), or improperly done digital stimulation. Likewise, constipation can be due to any combination of the following: not being on a regularly scheduled bowel regimen, low fiber diet, prolonged bed rest, taking certain medications including anticholinergics and narcotics, and even incomplete emptying during bowel care. Rectal bleeding can be attributed to hemorrhoids, rectal fissures, hard stools, trauma during digital stimulation of the anus, or GI bleeding. Diarrhea can be due to a multitude of causes including overuse of laxatives or stool softeners, current infection, taking antibiotics, stress, constipation, and potentially intake of coffee, tea, soft drinks or spicy foods. History should also include defecation or bowel care frequency and medication use. Daily fluid intake, diet (amount of fiber intake and calorie frequency), activity level, components of bowel care, time for bowel program, and characteristics (amount, consistency, presence of blood) of the stool should also be explored.7 Standardized assessment forms exist, such as the International SCI Bowel Function Basic Data Set, SCI-Quality of Life (SCI-QOL), and Neurogenic Bowel Dysfunction (NBD) score.1

In addition to the provided information, the assessment and management of neurogenic bowel dysfunction should also encompass psychological and social factors that can impact bowel function and overall well-being. Patients with neurological conditions may experience psychological distress, such as anxiety or depression, which can influence their ability to adhere to bowel management programs and affect treatment outcomes. Therefore, it’s essential to include psychological screening and support as part of the comprehensive care plan for individuals with neurogenic bowel dysfunction.10

Physical examination

The patient’s physical examination should be performed at onset and annually thereafter in stable situations. The examination should include a complete abdominal assessment, rectal examination, assessment of anal sphincter tone, anal sensation and voluntary contraction, and elicitation of anocutaneous and bulbocavernosus reflexes to determine if the patient has reflexic or areflexic bowel.8,11

Functional assessment

Assessment should include patient’s ability to learn and/or to direct others with a bowel program, sitting tolerance, sitting balance, upper limb strength and proprioception, upper limb function, spasticity, transfer skills, actual and potential risks to skin, home accessibility, and equipment needs. This assessment should occur for both the patient and caregiver.8

Laboratory studies

Annual stool testing for occult blood should occur for patients over the age of 50. For patients experiencing diarrhea of unknown etiology, stool examination for fecal leukocytes, clostridium difficile toxin, and ova and parasites may be helpful in searching for a diagnosis. Serum electrolyte levels may be monitored, especially in patients experiencing chronic diarrhea or prolonged fecal retention, to evaluate for electrolyte imbalances such as hypokalemia or hypernatremia. Blood tests such as complete blood count (CBC) and inflammatory markers like C-reactive protein (CRP) may also be useful in assessing for signs of inflammation or infection, particularly in patients with diarrhea of unknown etiology.7,11

Imaging

Fecal retention and megacolon are common diagnoses in patients with neurogenic bowel, thus flat plate x-ray of the abdomen may be warranted in patients with obstipation or constipation and is useful to assess fecal load. Abdominal CT can be useful to further delineate emergent vs non-emergent GI issues including obstruction.1 After age 50, colonoscopies, sigmoidoscopies, double-contrast barium enemas or computerized tomographic (CT) colonography (virtual colonoscopy) should be performed every 5-10 years, as recommended by screening guidelines to detect early signs of colorectal cancer and other gastrointestinal conditions in this population.7

Supplemental assessment tools

A dietary record and bowel care record can be useful to determine appropriate diet and bowel program changes. Bowel care record should include position, stimulation method, assistive techniques, time to results, and stool properties (amount, color, consistency).7 Colonic transit time testing with radiopaque markers, scintigraphy or a wireless motility capsule may be useful to confirm pathophysiology and assess response to treatment. Anorectal manometry (ARM) with/without pelvic EMG and pudendal nerve conduction studies may be useful to assess pelvic floor dysfunction and dyssynergia in motor incomplete injuries and can help distinguish constipation from fecal incontinence. The Balloon Expulsion Test (BET) is commonly conducted ARM. It assesses the function of the pelvic floor and rectal sphincter by measuring how well and for how long a balloon-tipped catheter can be expelled from the rectum during simulated defecation.12,13 Defecography can be used when ARM is inconclusive.1

Environmental

The home environment should be evaluated, and appropriate adaptive equipment for bowel care should be prescribed. Commonly, shower chairs with seats designed to allow access to the perineal area are necessary. Padded seats and tilt-in-space features can be beneficial.  The equipment should be inspected and fit assessed to avoid pressure ulcers related to equipment.1,7,11

Social role and social support system

The patient’s and caregiver’s knowledge and performance of, and confidence in, the recommended bowel management program should be assessed at each follow-up appointment.  Identifying and addressing any barriers to learning or implementing the program, including mental health issues, cognitive impairment, literacy levels, language barriers, readiness to learn, and cultural considerations, is essential for optimizing patient outcomes and adherence to the prescribed regimen.1

Rehabilitation Management and Treatments

Available or current treatment guidelines

Clinical Practice guidelines from the Consortium of Spinal Cord Medicine were updated in 2020.1 The goals of an effective bowel program are to provide predictable and effective elimination within a reasonable amount of time, reduce unplanned evacuations, reduce evacuation problems and gastrointestinal complaints, and to ultimately prevent chronic overdistension of the bowel. The well-designed bowel program should take into account attendant care, personal goals, life schedules, role obligations of the individual, and self-rated quality of life. In order to prevent complications, a bowel program should be initiated early and should be scheduled at the same time of the day to establish a habit-forming response. Additionally, ingesting food or liquids about thirty minutes before bowel care may stimulate the gastrocolic response, facilitating bowel movements. The frequency of bowel care should be individualized based on factors such as dietary intake, activity level, type of impairment, and pre-injury bowel habits. Typically, bowel care is scheduled every 1-2 days to prevent chronic colorectal overdistention. However, the specific frequency may vary depending on individual circumstances.8 While there is conflicting evidence regarding the effectiveness of abdominal massage, it’s important to note that the Valsalva maneuver is not recommended due to potential risks. Fiber supplementation, particularly with bulk-forming laxatives such as psyllium and FiberCon, is commonly used to manage bowel dysfunction, especially in patients with areflexic bowel. These agents can help promote regular bowel movements and alleviate constipation.14 

For more detailed information on bowel care agents, readers are directed to consult relevant sources cited elsewhere.1 These recommendations underscore the importance of individualized bowel management approaches tailored to each patient’s specific needs and circumstances.

Components of a bowel management program include1

  • Diet and fluid management
  • Physical activity
  • Oral medications
  • Rectal medications
  • Scheduled bowel care
  • Rectal evacuation methods

Overview of Basic Bowel Management According to Type of Bowel Dysfunction1

Reflexic BowelAreflexic Bowel
Adequate fluid and fiber intake, exercise, and individual care planAdequate fluid and fiber intake, exercise, and individual care plan
Daily but minimum 3 times/weekOne or more times per day
Goal Bristol stool scale 3-4Goal Bristol stool scale 3-4 (towards 3)
Rectal stimulants 
Digital rectal stimulation and manual evacuationManual removal
Oral medicationsOral medications
  • Reflexic bowel: Initial bowel care may consist of a chemical stimulant onto the rectal mucosa. After waiting for the stimulant to activate, the patient is placed in an upright or side-lying position and digital stimulation is performed until evacuation occurs. The goal for stool consistency is soft formed, allowing easy evacuation with rectal stimulation.7,12
  • Areflexic bowel: Initial bowel care may consist of upright or side-lying position, performing gentle manual evacuation until the rectum is stool free. The goal for stool consistency is firm formed stool that can be retained between bowel care sessions and allow easy manual evacuation.7,11

It is essential to emphasize the comprehensive approach to managing neurogenic bowel dysfunction, which includes dietary modifications, adequate fluid intake, physical activity, and oral medications to achieve and maintain appropriate stool consistency. Changes to the bowel program should be made systematically, adjusting one factor at a time (such as diet, fluids, activity level, schedule, position, medications, or assistive techniques) to optimize effectiveness while closely monitoring the patient’s response and involving the caregiver in the process. Adjustments to the bowel program are made based on the response to treatment and should closely involve the patient and caregiver. Continuous monitoring for gastrointestinal or intra-abdominal complications is paramount, particularly as aging can influence bowel function, necessitating modifications to the management plan over time.1,7

When conservative measures are insufficient, other rectal evacuation methods may be considered. Intermittent use of enemas can help alleviate constipation, while transanal irrigation (TAI) may be beneficial for patients with ineffective basic bowel programs. TAI involves pumping fluid into the colon via a cone or catheter while on a commode or toilet, with evidence supporting its effectiveness in reducing constipation, incontinence, and defecation time. In cases of severe bowel dysfunction resistant to conservative treatments, surgical interventions may be necessary as a last resort.1,4 Pulsed irrigation can be used for impaction in a hospital/clinic setting.1

Surgical procedures: surgical interventions are reserved for severe bowel dysfunction when other treatments have failed, and after thorough education regarding risks, benefits, and complications. Colostomy, the most common surgical option, and the Malone antegrade continence enema (MACE) can significantly improve quality of life, but their implementation should follow thorough education regarding risks, benefits, and potential complications.1,7,11

Patient & family education

Patient and family education play a crucial role in the effective management of neurogenic bowel dysfunction. It is essential to ensure that patients and their caregivers have a comprehensive understanding of the different types of neurogenic bowel dysfunction and the specific bowel care programs required to maintain proper care. Training on the bowel care program should be provided to both the patient and caregivers, including education on potential complications that may arise.

Moreover, social and emotional support should be readily available to help patients and their families navigate the challenges associated with neurogenic bowel dysfunction. This support can be instrumental in managing the physical, social, and psychological impact of the condition, enhancing overall well-being and quality of life.

The Consortium for Spinal Cord Medicine Consumer Guideline on Neurogenic Bowel serves as an invaluable resource for patients and families, offering valuable information and guidance on managing neurogenic bowel dysfunction. This resource can be beneficial for individuals affected by neurogenic bowel dysfunction, even when spinal cord injury is not the underlying cause, providing valuable insights into effective management strategies and enhancing patient and caregiver empowerment.15

Cutting Edge/Emerging and Unique Concepts and Practice

Newer oral medications approved for chronic constipation or irritable bowel syndrome with constipation (IBS-C) may also be considered as potential treatment options for individuals with neurogenic bowel dysfunction. These medications include chloride-channel activators (such as linaclotide, plecanatide, and lubiprostone), serotonin 4 agonists (such as prucalopride), and bile-acid analogs (such as chenodeoxycholic acid). However, their efficacy specifically in the context of neurogenic bowel dysfunction remains unclear and requires further research and clinical evaluation.

Furthermore, emerging therapeutic modalities such as functional magnetic stimulation and various forms of functional electrical stimulation are being investigated as potential interventions for neurogenic bowel dysfunction. Functional magnetic stimulation utilizes a magnetic field to stimulate spinal nerves, with small observational studies showing promise in reducing colonic transit time. However, the level of evidence for its effectiveness remains low, and larger, well-designed studies are needed to establish its efficacy definitively.

Similarly, functional electrical stimulation modalities, including sacral nerve stimulation, sacral anterior root stimulation, posterior tibial nerve stimulation, e-stimulation of abdominal muscles, perianal e-stimulation, and epidural e-stimulation, are under investigation for their potential role in managing neurogenic bowel dysfunction. Despite some promising findings in preliminary studies, the overall quality of evidence remains low, highlighting the need for further research to determine the optimal use and effectiveness of these interventions in clinical practice.6,9,10

Gaps in the Evidence-Based Knowledge

Further research is imperative to deepen our understanding of the pathophysiology underlying neurogenic bowel dysfunction, with particular attention to elucidating the influence of the gut microbiome. Comprehensive investigations should explore the interplay between neurological factors, gastrointestinal physiology, and environmental influences in shaping the course of this condition. Moreover, there is a pressing need for high-quality studies to elucidate the impact of dietary interventions, supplements, fiber, and probiotics on the effective management of neurogenic bowel dysfunction. Additionally, considering the diverse etiologies and presentations of this condition, tailored approaches to management based on individual patient characteristics warrant further exploration and validation through rigorous research methodologies.

References

  1. Consortium for Spinal Cord Medicine Clinical practice guidelines: Management of Neurogenic Bowel Dysfunction in Adults after Spinal Cord Injury. 2020. https://pvacf.org/wp-content/uploads/2020/10/CPG_Neurogenic-Bowel-Recommendations.single-6.pdf. Accessed June 27, 2024.
  2. Higgins PD, Johanson JF. Epidemiology of constipation in North America: A systematic review. American Journal of Gastroenterology. 2004;99:750-759.
  3. Preziosi G, Emmanuel A. Neurogenic bowel dysfunction: Pathophysiology, clinical manifestations and treatment. Expert review of gastroenterology & hepatology. 2009;3(4):417-423.
  4. Coggrave M, Norton C, Cody JD. Management of faecal incontinence and constipation in adults with central neurological diseases. Cochrane Database of Systematic Reviews 2014, Issue 1. Art. No.: CD002115.
  5. Mosiello, G., Safder, S., Marshall, D., Rolle, U., & Benninga, M. A. (2021). Neurogenic Bowel Dysfunction in Children and Adolescents. Journal of clinical medicine, 10(8), 1669. https://doi.org/10.3390/jcm10081669
  6. Cotterill N, Madersbacher H, Wyndaele JJ, et al. Neurogenic bowel dysfunction: Clinical management recommendations of the Neurologic Incontinence Committee of the Fifth International Consultation on Incontinence 2013. Neurourology and Urodynamics. 2018;37:46-53.
  7. Consortium for Spinal Cord Medicine. Clinical practice guidelines: neurogenic bowel management in adults with spinal cord injury. Journal of Spinal Cord Medicine. 1998;21:248-293.
  8. Rodriguez GM, Steins SA. Neurogenic Bowel: Dysfunction and Rehabilitation. In: Braddom RL, ed, Physical Medicine and Rehabilitation. Vol 1. 6th ed. Philadelphia, PA: Saunders; 2021:407-429.
  9. Tulsky, D. S., Kisala, P. A., Tate, D. G., Spungen, A. M., & Kirshblum, S. C. (2015). Development and psychometric characteristics of the SCI-QOL Bladder Management Difficulties and Bowel Management Difficulties item banks and short forms and the SCI-QOL Bladder Complications scale. The journal of spinal cord medicine, 38(3), 288–302. https://doi.org/10.1179/2045772315Y.0000000030
  10. Ture S.D., Ozkaya G., Sivrioglu K. Relationship between neurogenic bowel dysfunction severity and functional status, depression, and quality of life in individuals with spinal cord injury. J. Spinal Cord Med. 2022:1–9. doi: 10.1080/10790268.2021.2021043.
  11. Stiens S, Goetz L, Strayer J. Neurogenic bowel dysfunction: Evaluation and adaptive management. In: O’Young B, Young M, Stiens S, eds. Physical Medicine and Rehabilitation Secrets. 4th ed. Philadelphia, PA: Mosby Elsevier; 2008:531-538.
  12. Krogh K., Christensen P. Neurogenic colorectal and pelvic floor dysfunction. Best Pract. Res. Clin. Gastroenterol. 2009;23:531–543. doi: 10.1016/j.bpg.2009.04.012.
  13. Kurze, I., Geng, V., & Böthig, R. (2022). Guideline for the management of neurogenic bowel dysfunction in spinal cord injury/disease. Spinal cord, 60(5), 435–443. https://doi.org/10.1038/s41393-022-00786-x
  14. Appendix 4; Bowel Care Medications. In: Gonzalez-Fernandez M, Friedman JD, eds. Physical Medicine and Rehabilitation Pocket Companion. Vol 1. 1st ed. New York, NY: Demos; 2011:326-3279.
  15. Consortium for Spinal Cord Medicine. Neurogenic bowel: what you should know. https://pva.org/wp-content/uploads/2021/09/consumer-guide_neurogenic-bowel.pdf. Accessed June 27, 2024.

Original Version of the Topic

Michelle Poliak, MD, Sara Liegel, MD. Neurogenic Bowel. 11/10/2011.

Previous Revision(s) of the Topic

Michelle Poliak, MD, Sara Liegel, MD. Neurogenic Bowel. 9/18/2015.

Philip Chen, MD. Neurogenic Bowel. 5/12/2021

Author Disclosures

Ashlyn Brown, MD
Nothing to Disclose

Ton La Jr, MD, JD
Nothing to Disclose

Felicia Skelton, MD
VA RR&D, research grant, Investigator
VA HSR, research grant, Investigator Craig Neilsen Foundation, research grant, Investigator